Free radicals generation by the inflammatory cells.

One of the most impressive property of the leucocytes is that of changing the oxidative metabolism during various functions. When challenged with phagocytosable particles or with membrane perturbing agents such as chemotactic factors, detergents, lectins and other ligands, granulocytes and mononuclear phagocytes undergo a dramatic increase of oxygen consumption which is associated with the production of superoxide anion (O-2), of hydrogen peroxide (H2O2) and of hydroxyl radical (OH.). These events are referred to as "respiratory burst' . Most of the functions of the inflammatory cells (killing of micro-organisms, tissue damage, amplification of the inflammatory process) are linked to the production, to the fate and to the chemical reactivity of these highly reactive compounds. The authors examine the following aspects: (i) the mechanism responsible for the respiratory burst; (ii) the conditions present in the inflammatory site that induces the metabolic activation of leucocytes; (iii) the variability of the respiratory burst in different types of leucocytes; (iv) the fate, the interrelationships and the reactivity of the intermediate products of oxygen reduction; (v) the relationships between the inflammatory process and the production of free radicals by the inflammatory cells.